Yesterday was the deadline for Michele Bachmann to accept University of Pennsylvania bioethicist Arthur Caplan's challenge to produce a single person who's developed "mental retardation" from Gardasil. Caplan offered to donate $10,000 to a charity of her choice if she could just locate the mystery woman whose daughter became disabled after being vaccinated for HPV. Bachmann never responded, probably because she's been plugging her ears and humming to herself to prevent scientific facts from seeping in. Caplan says he's still glad he made bet because, "Politicians shouldn't get away with hearsay. We need to hold candidates responsible for their sources."